CN115462935B

CN115462935B - Double-layer acetabular cup prosthesis and preparation method thereof

Info

Publication number: CN115462935B
Application number: CN202210969871.9A
Authority: CN
Inventors: 吴仲恒; 张君
Original assignee: Guangzhou Weima Veterinary Technology Service Co ltd
Current assignee: Guangzhou Weima Veterinary Technology Service Co ltd
Priority date: 2022-08-12
Filing date: 2022-08-12
Publication date: 2024-08-06
Anticipated expiration: 2042-08-12
Also published as: CN115462935A

Abstract

The invention discloses a double-layer acetabular cup prosthesis and a preparation method thereof, wherein the double-layer acetabular cup prosthesis comprises: the upper end of the outer cup is provided with a first convex spherical surface which can be connected with the acetabular fossa, the lower end surface of the outer cup is provided with a first concave spherical surface with downward openings and a limiting groove, the first concave spherical surface is provided with an annular groove with a circular arc cross section, the annular groove is formed by rotating a central axis extending up and down of the first concave spherical surface as a rotation axis, and the limiting groove penetrates through the first concave spherical surface; the inner lining cup is provided with a second concave spherical surface capable of being connected with the inner lining prosthesis on the lower end surface of the inner lining cup, a second outer convex spherical surface in adaptive connection with the first concave spherical surface is arranged at the upper end of the inner lining cup, and an annular convex part in adaptive connection with the annular groove and a limiting part in adaptive connection with the limiting groove are arranged on the second outer convex spherical surface. The invention can realize the connection of the outer cup and the inner liner cup, avoid the movement of the inner liner cup relative to the outer cup, and the inner liner cup is easy to assemble and disassemble in the annular groove, thereby facilitating the repair of the double-layer acetabular cup prosthesis and avoiding the integral disassembly of the double-layer acetabular cup prosthesis.

Description

Double-layer acetabular cup prosthesis and preparation method thereof

Technical Field

The invention belongs to the technical field of medical appliances, and particularly relates to a double-layer acetabular cup prosthesis and a preparation method thereof.

Background

Joint diseases caused by osteoarthritis, rheumatoid arthritis, bone infection or blood supply deficiency are often the cause of joint replacement surgery. Arthritis usually occurs in weight-bearing joints such as hip joints and knee joints, and it causes cartilage damage to the ends of bones, causing pain and stiffness to the joints, and thus deep joint damage needs to be repaired by joint replacement surgery. Such joint diseases are not only present in humans, but are also common in pet animals such as dogs, cats, and the like. In artificial hip arthroplasty, the damaged portion of the hip joint is resected and replaced with prosthetic components made of metal, ceramic and rigid plastic, helping to relieve pain and improve the functionality of the hip joint.

The artificial acetabular cup prosthesis is an implant prosthesis widely used in hip joint replacement, the structure of the hip joint prosthesis generally comprises an acetabular cup, a femoral head and a femoral stem, the acetabular cup is an important bearing and force transmission component for connecting a trunk and a lower limb, can be directly contacted with bone tissues, and is a key for guaranteeing the stable use of the implant prosthesis.

The existing acetabular cup prosthesis generally adopts an integrated metal prosthesis, the outer surface of the acetabular cup prosthesis is generally fixed in contact with the acetabular socket through bone cement or a biological coating, and the inner surface of the acetabular cup prosthesis is matched with a polyethylene lining. Along with the progress of scientific and technological, the acetabular cup prosthesis adopts bilayer structure, including metal lining and metal acetabular cup, the polyethylene lining has the interior concave surface that is used for being connected with the metal bulb, the metal lining has the interior concave surface of being connected with the polyethylene lining, metal acetabular cup has interior conical surface, the metal lining has the outer conical surface, metal acetabular cup and metal lining realize being connected through conical surface cooperation, so the design can increase the mobility of acetabular cup prosthesis, reduce the risk of postoperative joint dislocation. However, the metal inner liner and the metal acetabular cup are easy to slightly move in the vertical direction in actual use, so that the problems of rapid abrasion and difficult maintenance of the metal inner liner are caused.

Disclosure of Invention

The invention aims to provide a double-layer acetabular cup prosthesis, which solves one or more technical problems existing in the prior art.

In addition, the invention also provides a preparation method for preparing the double-layer acetabular cup prosthesis.

The technical scheme adopted for solving the technical problems is as follows:

the invention discloses a double-layer acetabular cup prosthesis, which comprises:

The upper end of the outer cup is provided with a first convex spherical surface which is used for being connected with an acetabular fossa, the lower end surface of the outer cup is provided with a first concave spherical surface with downward openings and a limiting groove, the first concave spherical surface is provided with an annular groove, the annular groove is formed by rotating a central axis extending up and down of the first concave spherical surface as a rotation axis, the cross section of the annular groove is arc-shaped, and the limiting groove penetrates through the first concave spherical surface;

The inner lining cup, its lower terminal surface is equipped with the second indent sphere that is used for being connected with the inner lining prosthetic, the upper end of inner lining cup is equipped with the outer protruding sphere of second, the outer protruding sphere of second is connected with first indent sphere adaptation, the outer protruding sphere of second is equipped with annular convex part and spacing portion, the axis that the outer protruding sphere of annular convex part of second extended from top to bottom is rotatory as the axis of rotation and forms, annular convex part and annular groove adaptation are connected, spacing portion and spacing groove adaptation are connected.

The double-layer acetabular cup prosthesis provided by the invention has at least the following beneficial effects: the outer cup is fixedly connected with the acetabular fossa through the first convex spherical surface, so that the stress in the acetabular fossa can be more effectively distributed on the outer cup, and the looseness of the double-layer acetabular cup prosthesis caused by poor bone growth due to stress concentration is prevented; the first concave spherical surface of the outer cup is provided with an annular groove, the second convex spherical surface of the inner liner cup can be inserted into and adaptively connected with the first concave spherical surface of the outer cup, meanwhile, the annular convex part on the inner liner cup can be adaptively connected with the annular groove of the outer cup, so that the inner liner cup is prevented from moving up and down relative to the outer cup, and the limiting part on the inner liner cup can be clamped in the limiting groove on the outer cup, so that the inner liner cup is prevented from rotating along an axis extending up and down relative to the outer cup; the outer cup and the inner liner cup are detachable, the acetabular cup prosthesis with a double-layer structure can be formed, the outer cup and the inner liner cup are connected through the structure, the inner liner cup is prevented from moving relative to the outer cup in the using process, the cross section of the annular groove and the annular convex part is arc-shaped, the surface is smooth, the inner liner cup is easy to insert into or remove from the first concave spherical surface, accordingly, the double-layer acetabular cup prosthesis is convenient to repair, and the whole disassembly of the double-layer acetabular cup prosthesis is avoided.

As a further improvement of the technical scheme, the limiting grooves are formed in a plurality of positions and are arranged around the circumference of the central axis extending up and down of the first concave spherical surface, the limiting parts are formed in a plurality of positions, and the limiting parts are arranged corresponding to the limiting grooves. The outer cup is provided with a plurality of limit grooves, the limit grooves are arranged around the circumference of the central axis of the first concave spherical surface, the lining cup is provided with a plurality of limit parts, the limit parts are arranged around the circumference of the central axis of the first convex spherical surface, and the limit parts and the limit grooves are correspondingly arranged to promote the outer cup to be stressed uniformly.

As the further improvement of above-mentioned technical scheme, the lower terminal surface of outer cup is equipped with first chamfer, first chamfer with the axis of the upper and lower extension of first indent sphere is rotatory as the rotation axis and forms, first chamfer is upwards in the inboard of first indent sphere to the camber, the lower terminal surface of inside lining cup is equipped with the second chamfer, the second chamfer with the axis of the upper and lower extension of second epirelief sphere is rotatory as the rotation axis and forms, the second chamfer is upwards in the inboard of second epirelief sphere to the camber, the inclination of second chamfer and first chamfer is unanimous.

The first chamfer is arranged at the lower end of the outer cup, so that burrs remained at the edge of the lower end of the outer cup after molding can be removed, the outer cup is more convenient to mount and implant into an acetabular fossa, and the damage to the femur when the femur is contacted with the outer cup due to the over sharp edge of the outer cup is avoided; the lining cup corresponds to and sets up the second chamfer, and the inclination of second chamfer and first chamfer is unanimous, makes the lower terminal surface of lining cup can be parallel and level with the lower terminal surface of outer cup, avoids the femur to damage because of its contact with the lining cup.

As a further improvement of the above technical solution, the double-layered acetabular cup prosthesis further comprises a set screw; the outer cup is provided with a countersunk hole, the countersunk hole penetrates through the first concave spherical surface and the first convex spherical surface respectively, the fixing screw is matched with the countersunk hole, and the thread section of the fixing screw is located outside the first concave spherical surface. The fixing screw penetrates through the countersunk head hole of the outer cup and is connected and fixed with the acetabular fossa, so that the double-layer acetabular cup prosthesis is tightly implanted into the acetabular fossa, the countersunk head hole can provide an accommodating space for the head of the fixing screw, and the head of the fixing screw is prevented from being contacted with the second outer convex spherical surface of the inner liner cup.

As a further improvement of the above technical solution, the first convex spherical surface is provided with a porous structural layer. The surface of the outer cup, which is contacted with the acetabular socket, is provided with a porous structure, and biological bone ingrowth can be formed between the porous structure and primary muscles and bone tissues, so that the stability of the double-layer acetabular cup prosthesis after implantation is improved.

As a further improvement of the technical scheme, the opening of the second concave spherical surface is arranged downwards, and the second concave spherical surface is provided with a wear-resistant coating. The surface of the lining cup connected with the lining prosthesis is provided with a wear-resistant coating, so that the wear resistance of the lining cup is improved, and the service life of the double-layer acetabular cup prosthesis is prolonged.

As a further improvement of the technical scheme, the preparation material of the outer cup and the inner liner cup is one of tantalum or tantalum alloy, cobalt chromium molybdenum alloy, titanium or titanium alloy. The outer cup and the inner liner cup are made of one material of tantalum or tantalum alloy, cobalt chromium molybdenum alloy, titanium or titanium alloy, so that the outer cup and the inner liner cup have high strength, and the double-layer acetabular cup prosthesis can be ensured to have high bearing capacity after being implanted.

In addition, the invention also provides a preparation method for preparing the double-layer acetabular cup prosthesis, which comprises the following steps of:

Designing a three-dimensional model of the outer cup and a three-dimensional model of the inner liner cup according to the sizes of the acetabular fossa and the femoral head;

Matching simulation is carried out on the three-dimensional model of the outer cup and the three-dimensional model of the inner lining cup;

manufacturing the outer cup by adopting a 3D printing technology according to the three-dimensional model of the outer cup;

And manufacturing the lining cup by adopting a machining process according to the three-dimensional model of the lining cup.

The preparation method of the double-layer acetabular cup prosthesis provided by the invention has at least the following beneficial effects: establishing a three-dimensional model of the outer cup and a three-dimensional model of the inner liner cup according to the actual sizes of the acetabular fossa and the femoral head, enabling the outer cup and the inner liner cup to be matched with each other, then manufacturing an outer cup real object by using the three-dimensional model of the outer cup through a 3D printing technology, and manufacturing the inner liner cup by using the three-dimensional model of the inner liner cup through a machining process; the double-layer acetabular cup prosthesis adopts a composite preparation method, so that the matching degree between the outer cup and the inner liner cup can be ensured to reach the standard; because the second outer convex spherical surface and the second inner concave spherical surface of the lining cup need high smoothness, the friction coefficient between the lining cup and the outer cup and between the lining cup and the lining prosthesis is reduced, and a mechanical processing mode is directly adopted, the second outer convex spherical surface and the second inner concave spherical surface can be promoted to obtain proper smoothness, the roughness is reduced, the abrasion is reduced, and the service life is prolonged.

As a further improvement of the above technical solution, the step of manufacturing the liner cup according to the three-dimensional model of the liner cup by using a machining process includes the steps of:

machining the lining cup according to a three-dimensional model of the lining cup in a machining mode, wherein the lower end of the lining cup is provided with a second concave spherical surface with a downward opening;

and preparing the wear-resistant coating on the second concave spherical surface of the lining cup by adopting a PVD coating process.

After the lining cup is prepared, a layer of wear-resistant coating is plated on the second concave spherical surface of the lining cup through a PVD coating technology, so that the binding force between the wear-resistant coating and the lining cup is promoted to be larger, the wear-resistant coating on the lining cup has the advantages of high hardness, high wear resistance, good corrosion resistance, good chemical stability and the like, and the durability of the double-layer acetabular cup prosthesis is improved.

As a further improvement of the technical scheme, the 3D printing technology is a laser 3D printing SLM technology, the laser power is 150W to 300W, the scanning speed is 600mm/s to 1200mm/s, the powder spreading thickness is 0.03mm to 0.06mm, and the scanning interval is 0.05mm to 0.1mm; or the 3D printing technology is an electron beam 3D printing EBM technology, the power of the electron beam is 1kW to 2kW, the scanning speed is 800mm/s to 4000mm/s, and the powder spreading thickness is 0.05 to 0.1mm. The outer cup is manufactured by a laser 3D printing SLM technology or an electron beam 3D printing EBM technology, so that materials can be saved, the speed of a finished product is high, the manufactured outer cup is high in precision, and the outer cup can be matched with an acetabular cup and an inner liner cup.

Drawings

The invention is further described below with reference to the drawings and examples;

FIG. 1 is an exploded view of a construction of a dual layer acetabular cup prosthesis according to an embodiment of the invention;

FIG. 2 is a perspective view of a construction of a dual layer acetabular cup prosthesis according to an embodiment of the invention;

FIG. 3 is a perspective view of a dual layer acetabular cup prosthesis according to an embodiment of the invention in another view;

FIG. 4 is a top view of a dual layer acetabular cup prosthesis provided by an embodiment of the invention;

FIG. 5 is a cross-sectional view of section A-A of FIG. 4;

FIG. 6 is a cross-sectional view of section B-B of FIG. 4;

FIG. 7 is a perspective view of the structure of an outer cup provided by an embodiment of the present invention;

FIG. 8 is a perspective view of a set screw according to an embodiment of the present invention;

Fig. 9 is a flow chart of a method of preparing a dual layer acetabular cup prosthesis according to an embodiment of the invention.

The figures are marked as follows: 100. an outer cup; 110. a countersunk hole; 120. the first convex spherical surface; 130. a first concave spherical surface; 140. a limit groove; 150. an annular groove; 200. lining a cup; 210. an annular convex portion; 220. a limit part; 230. a second outwardly convex spherical surface; 240. a second concave spherical surface; 300. a fixing screw; 310. a threaded section; 320. a head; 330. an internal corner hole; 340. a cylindrical body.

Detailed Description

Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the accompanying drawings are used to supplement the description of the written description so that one can intuitively and intuitively understand each technical feature and overall technical scheme of the present invention, but not to limit the scope of the present invention.

In the description of the present invention, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present invention and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, if there is a word description such as "a plurality" or the like, the meaning of the plurality is one or more, the meaning of the plurality is two or more, and greater than, less than, exceeding, etc. are understood to exclude the present number, and above, below, within, etc. are understood to include the present number. The description of first, second, and third is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of technical features indicated.

In the description of the present invention, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present invention can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

With reference to fig. 1-9, several embodiments of the dual layer acetabular cup prosthesis of the invention and methods of making same are described below.

As shown in fig. 1 to 8, a first embodiment of the present invention provides a dual layer acetabular cup prosthesis disposed between an acetabular cup and a liner prosthesis made of polyethylene to organically couple the two. The dual layer acetabular cup prosthesis may be used in pets such as dogs and cats.

The structure of the dual layer acetabular cup prosthesis includes an outer cup 100 and a liner cup 200. The outer cup 100 and the inner cup 200 are made of metal materials, specifically, the materials used for manufacturing the outer cup 100 and the inner cup 200 comprise one of cobalt-chromium-molybdenum alloy, tantalum or tantalum alloy, titanium or titanium alloy and other materials, so that the outer cup 100 and the inner cup 200 have high strength, and the double-layer acetabular cup prosthesis can be guaranteed to have good bearing capacity after being implanted into a body.

The outer cup 100 is provided with a first convex spherical surface 120, and the first convex spherical surface 120 is located at the upper end part of the outer cup 100 and is used for being connected with an acetabular fossa. During actual implantation, the acetabular fossa has an inner concave spherical surface, so that the first outer convex spherical surface 120 of the outer cup 100 is matched with the inner concave spherical surface of the acetabular fossa, so that the outer cup 100 can be well installed on the acetabular fossa, the stress in the acetabular fossa can be more effectively distributed on the outer cup 100, and the loosening of the outer cup 100 caused by poor bone growth due to stress concentration is prevented.

Further, the first convex spherical surface 120 is provided with a porous structure layer. The thickness of the porous structure layer is 0.1mm to 1mm, the aperture of each hole is 0.15mm, the porous structure layer and the outer cup 100 are integrally formed, and the porous structure layer is paved on the whole first convex spherical surface 120. The outer cup 100 is attached to the bone by the porous structure layer, and after the outer cup 100 is implanted, biological bone ingrowth can be formed between the porous structure layer and the native muscle and bone tissue, so that the stability of the double-layer acetabular cup prosthesis after implantation is improved.

The outer cup 100 is provided with a first concave spherical surface 130. The opening of the first concave spherical surface 130 is disposed downward, and the first concave spherical surface 130 is located at the lower end of the outer cup 100. Specifically, the lower end surface of the outer cup 100 is concavely formed with a first concave spherical surface 130. The outer cup 100 is provided with a first concave spherical surface 130, which provides an installation space for the inner liner cup 200 to be inserted into the outer cup 100.

In this embodiment, the outer cup 100 is hemispherical, the first convex spherical surface 120 is hemispherical, as shown in fig. 5 and 6, the cross-sectional shape of the outer cup 100 on the vertical surface is semicircular, the cross-sectional shape of the first convex spherical surface 120 on the vertical surface is semicircular, the cross-sectional shape of the first concave spherical surface 130 on the vertical surface is circular arc, and the central angle is smaller than 180 °. The radius of the first concave spherical surface 130 is the difference between the radius of the first convex spherical surface 120 and the thickness of the outer cup 100, and the thickness of the outer cup 100 is thick in the middle and thin on both sides, as shown in fig. 5 and 6.

The central axes of the first convex spherical surface 120 and the first concave spherical surface 130 are arranged to extend in the up-down direction, and they are coincident. The side close to the central axis of the first concave spherical surface 130 is taken as the inner side, and the side far from the central axis of the first concave spherical surface 130 is taken as the outer side.

The outer cup 100 is provided with an annular recess 150. Specifically, the first concave spherical surface 130 is concavely formed with an annular groove 150, the annular groove 150 is formed by rotating 360 ° with the central axis of the first concave spherical surface 130 as a rotation axis, and the cross section of the annular groove 150 is circular arc-shaped, specifically, semicircular. An annular recess 150 is provided near the lower end of the outer cup 100.

The outer cup 100 is provided with a limiting groove 140, the opening of the limiting groove 140 is downward, and the limiting groove 140 is positioned at the lower end of the outer cup 100. Specifically, the lower end surface of the outer cup 100 is concavely formed with a limiting groove 140, the limiting groove 140 is located at the outer side of the first concave spherical surface 130, and the limiting groove 140 penetrates through the first concave spherical surface 130, so that the limiting groove 140 is communicated with the first concave spherical surface 130.

It is understood that the shape of the limiting groove 140 is various, and the shape of the limiting groove 140 may be triangular, trapezoidal, square from the bottom view. In this embodiment, the shape of the limiting groove 140 is square, and the connection between the limiting groove 140 and the first concave spherical surface 130 adopts an arc transition connection mode.

The liner cup 200 is provided with a second outwardly convex spherical surface 230. The second outer convex spherical surface 230 is located at the upper end of the inner liner cup 200, when the inner liner cup 200 is inserted into the first concave spherical surface 130 of the outer cup 100, the second outer convex spherical surface 230 can be connected with the first concave spherical surface 130 in an adapting manner, so that a spherical contact mode is adopted between the inner liner cup 200 and the outer cup 100, and the acting force applied by the inner liner cup 200 to the outer cup 100 can be uniformly distributed on the first concave spherical surface 130 of the outer cup 100.

In this embodiment, as shown in fig. 5 and 6, the cross-sectional shape of the liner cup 200 on the vertical surface is a sector shape without a center, and the sector shape is rotated 360 ° around a central axis extending up and down to form the liner cup 200. The second male spherical surface 230 has an arc-shaped cross section on the vertical surface, and the central angle is smaller than 180 °, so that the second male spherical surface 230 can be connected with the first female spherical surface 130 in a matching manner. The central axis of the second convex spherical surface 230 extends in the up-down direction.

Liner cup 200 is provided with annular boss 210. Specifically, the second outer convex spherical surface 230 is formed with an annular protrusion 210 in a protruding manner, the annular protrusion 210 is formed by rotating 360 ° with the central axis of the second outer convex spherical surface 230 as a rotation axis, the annular protrusion 210 and the liner cup 200 are integrally formed, and the cross section of the annular protrusion 210 is circular arc-shaped, specifically, semicircular, so that the annular protrusion 210 can be connected with the annular groove 150 in an adapting manner when the liner cup 200 is inserted into the outer cup 100.

Further, the liner cup 200 is provided with a stopper 220. Specifically, the second convex spherical surface 230 is formed with a limiting portion 220 protruding, the limiting portion 220 and the liner cup 200 are integrally formed, when the outer cup 100 is sleeved on the liner cup 200, the limiting portion 220 can be clamped into the limiting groove 140 and is connected with the limiting groove 140 in an adaptive manner, two side wall surfaces of the limiting portion 220 (i.e., wall surfaces located between the inner side and the outer side of the limiting portion 220) can be in contact with the inner wall surface of the limiting groove 140, and therefore the limiting portion 220 is limited by the limiting effect from the limiting groove 140, so that the liner cup 200 cannot rotate relative to the outer cup 100. The stopper 220 is located at the lower end surface edge of the liner cup 200.

Liner cup 200 is provided with a second concave spherical surface 240. The second concave spherical surface 240 is located at the lower end of the liner cup 200, specifically, the lower end surface of the liner cup 200 is concavely formed with the second concave spherical surface 240, the opening of the second concave spherical surface 240 is downward, and the liner cup 200 is connected with the polyethylene liner prosthesis through the second concave spherical surface 240. The central axis of the second concave spherical surface 240 coincides with the central axis of the second convex spherical surface 230. The liner cup 200 is of uniform thickness.

Further, the second concave spherical surface 240 is provided with a wear-resistant coating. The wear resistant coating may be a TiN coating (i.e., a titanium nitride coating) or a DLC coating (i.e., a diamond-like coating). The surface of the liner cup 200, which is connected with the liner prosthesis, is provided with a wear-resistant coating, so that the wear resistance of the liner cup 200 is improved, and the service life of the double-layer acetabular cup prosthesis is prolonged.

It can be appreciated that when the liner cup 200 is connected with the outer cup 100, the annular protrusion 210 on the liner cup 200 can be connected with the annular groove 150 of the outer cup 100 in an adapting way, so as to limit two degrees of freedom of the outer cup 100 and the liner cup 200, and self-lock the liner cup 200 in the outer cup 100, so that the liner cup 200 is effectively prevented from moving up and down relative to the outer cup 100, and the limit part 220 on the liner cup 200 can be clamped in the limit groove 140 on the outer cup 100, so as to prevent the liner cup 200 from rotating along the axis extending up and down relative to the outer cup 100. By the design, the lining cup 200 can be ensured to be stable relative to the outer cup 100 after being arranged on the outer cup 100, and the lining cup 200 is prevented from jogging relative to the outer cup 100 after the lining cup 200 is connected with the outer cup 100, so that the lining cup 200 is prevented from being worn too fast.

The outer spherical surface of the polyethylene liner prosthesis and the second concave spherical surface 240 of the liner cup 200 are smooth spherical surfaces, and when the double-layer acetabular cup prosthesis is used, the polyethylene liner prosthesis is connected with a metal ball head (namely a femoral head), and the outer spherical surface of the metal ball head and the inner spherical surface of the polyethylene liner prosthesis form a joint supporting surface; the outer spherical surface of the polyethylene liner prosthesis and the second concave spherical surface 240 of the liner cup 200 form an articulating bearing surface, which corresponds to a large diameter femoral head connected to the outer cup 100, enabling greater mobility. The second concave spherical surface 240 of the liner cup 200 and the outer spherical surface of the polyethylene liner prosthesis can move relative to each other, i.e., have a double-acting effect.

The outer cup 100 and the inner cup 200 are detachable independent bodies, can form an acetabular cup prosthesis with a double-layer structure, and can ensure the relative flexibility of the inner cup 200 and the inner prosthesis while increasing the strength. By arranging the structures of the annular convex part 210, the annular groove 150, the limiting part 220, the limiting groove 140 and the like, the connection between the outer cup 100 and the inner liner cup 200 is realized, and the inner liner cup 200 is prevented from moving relative to the outer cup 100 in the use process; moreover, the cross-sectional shapes of the annular groove 150 and the annular protrusion 210 are circular arc-shaped, and the surfaces are smooth, so that the liner cup 200 is easy to insert into the first concave spherical surface 130 or remove from the first concave spherical surface 130, thereby facilitating the repair of the double-layer acetabular cup prosthesis and avoiding the whole disassembly of the double-layer acetabular cup prosthesis.

It will be appreciated that, since the central angle of the first concave spherical surface 130 of the outer cup 100 is smaller than 180 ° and the central angle of the second convex spherical surface 230 of the inner cup 200 is smaller than 180 °, the cross-sectional shapes of the annular convex portion 210 and the annular groove 150 are circular arc shapes, when the inner cup 200 located on the outer cup 100 is pried, the inner cup 200 will deform to a certain extent and shrink inwards, so that the annular convex portion 210 can be easily separated from the annular groove 150, and the inner cup 200 is detached from the outer cup 100, thereby facilitating the repair of the inner cup 200. When the outer cup 100 is coupled with the inner liner cup 200, the inner liner cup 200 may be pressed into the first concave spherical surface 130 of the outer cup 100 by pressing.

As shown in fig. 2 and 7, one or more limit grooves 140 may be provided. In this embodiment, the number of the limiting grooves 140 and the limiting portions 220 is six, the six limiting grooves 140 are circumferentially arranged around the central axis of the first concave spherical surface 130, the included angle between two adjacent limiting grooves 140 is 60 °, the six limiting portions 220 are circumferentially arranged around the central axis of the second convex spherical surface 230, so that the six limiting portions 220 are correspondingly connected with the six limiting grooves 140, and the outer cup 100 is uniformly acted on by the acting force from the inner cup 200.

In some embodiments, as shown in fig. 5 and 6, the outer cup 100 is provided with a first chamfer, specifically, the first chamfer is located at the lower end surface of the outer cup 100, the first chamfer is formed by rotating 360 ° with the central axis of the first concave spherical surface 130 as the rotation axis, and the first chamfer is disposed obliquely upward from the inner side of the first concave spherical surface 130 to the outer side of the first concave spherical surface 130.

Similarly, the liner cup 200 is provided with a second chamfer, specifically, the second chamfer is located at the lower end surface of the liner cup 200, the second chamfer is formed by rotating 360 ° with the central axis of the second convex spherical surface 230 as the rotation axis, and the second chamfer is disposed obliquely upward from the inner side of the second convex spherical surface 230 to the outer side of the second convex spherical surface 230. The inclination angles of the second chamfer and the first chamfer are consistent, an included angle alpha is formed between the first chamfer and the horizontal plane and between the second chamfer and the horizontal plane, and the included angle alpha can be 10 degrees, 25 degrees, 30 degrees and the like.

The first chamfer is arranged at the lower end of the outer cup 100, so that burrs remained at the edge of the lower end of the outer cup 100 after molding can be removed, the outer cup 100 is easier to implant into an acetabular fossa, and the damage to the femur when the femur contacts with the outer cup 100 due to the over sharp edge of the outer cup 100 is avoided; the lining cup 200 is correspondingly provided with the second chamfer, the inclination angle of the second chamfer is consistent with that of the first chamfer, the lower end face of the lining cup 200 is enabled to be flush with the lower end face of the outer cup 100, and the femur is prevented from being damaged due to contact with the lining cup 200.

As shown in fig. 1, 5 and 6, the lower end surface of the liner cup 200 and the lower end surface of the outer cup 100 are inclined planes and are flush. In addition, a certain gap exists between the limiting part 220 and the limiting groove 140 in the radial direction of the outer cup 100, the thickness of the limiting part 220 is consistent, the limiting groove 140 and the limiting part 220 are inclined upwards from inside to outside, in addition, the thickness of the outer cup 100 is thick in the middle and thin at two sides, the design is adopted, a disassembling tool can be inserted into the gap between the limiting part 220 and the limiting groove 140, an inward acting force is applied to the lining cup 200 through prying operation, the lining cup 200 is driven to deform, meanwhile, the outer cup 100 is also driven to deform by an outward acting force applied by the disassembling tool, the gap between the outer cup 100 and the lining cup 200 is enlarged, the annular convex part 210 can be driven to deviate from the annular groove 150, and the downward acting force is applied to the lining cup 200, so that the annular convex part 210 is driven to move downwards relative to the outer cup 100, and the inner wall surface of the first concave spherical surface 130 is abutted in the downward moving process, so that the lining cup 200 is driven to maintain a deformed state; when the liner cup 200 is removed from the first concave spherical surface 130, the liner cup 200 is removed from the outer cup 100, facilitating the revision of the dual-layer acetabular cup prosthesis without removing the outer cup 100 from the acetabular cup.

In some embodiments, as shown in fig. 1-8, the dual layer acetabular cup prosthesis further includes a set screw 300.

The outer cup 100 is provided with a countersunk hole 110, the countersunk hole 110 penetrates from the first concave spherical surface 130 to the first convex spherical surface 120, the fixing screw 300 is matched with the countersunk hole 110, and the thread section 310 of the fixing screw 300 is positioned outside the first concave spherical surface 130. Counterbore 110 may be a threaded bore.

The threaded section 310 of the fixing screw 300 passes through the countersunk head 110 of the outer cup 100 and is fixedly connected with the acetabular fossa, so that the double-layer acetabular cup prosthesis is tightly implanted into the acetabular fossa, and the countersunk head 110 can provide an accommodating space for the head 320 of the fixing screw 300, so that the head 320 of the fixing screw 300 is prevented from being contacted with the second externally convex spherical surface 230 of the inner liner cup 200. For better fixing the outer cup 100 to the acetabular fossa, the number of the fixing screws 300 and the counter sunk holes 110 is plural, and the sizes of the counter sunk holes 110 and the fixing screws 300 are adapted. The set screw 300 may be 1.5mm, 2.0mm, or 2.4mm in diameter. The set screw 300 may be a stainless steel screw.

Before the counter bore 110 is made on the outer cup 100, the position of the counter bore 110 is set according to CT scanning data, and the counter bore 110 is arranged on two sides of the outer cup 100, which are close to the bone-rich primary bones, so that fastening tension can be provided between the outer cup 100 and the primary bones. The number and distribution of the countersunk holes 110 are determined according to the actual bone structure. In this embodiment, the fixing screw 300 and the countersunk holes 110 are five, three countersunk holes 110 are formed on one side of the outer cup 100, two countersunk holes 110 are formed on the opposite side of the outer cup 100, the countersunk position of the countersunk holes 110 is located on the first concave spherical surface 130 of the outer cup 100, the radius of the countersunk holes 110 is 1.9mm, and the depth is 2.3mm.

In other embodiments, the outer cup 100 is secured to the acetabular socket by a bone cement or biocoating, but bone cement has certain side effects on the replacement implant patient, and the biocoating risks coming off during use. With respect to bone cement and biological coatings, the present embodiment employs set screw 300 to enable the outer cup 100 to be tightly secured in the acetabular fossa, with little tendency to fall out, and without adverse effects on the patient.

The head 320 of the set screw 300 is provided with internal corner holes 330, and the internal corner holes 330 may be internal four corner holes, internal hexagonal holes or quincuncial holes. The fixing screw 300 is provided with a cylindrical portion 340, the cylindrical portion 340 is located in the internal corner hole 330, the central axis of the cylindrical portion 340 coincides with the central axis of the fixing screw 300, and the cylindrical portion 340 and the fixing screw 300 are integrally formed.

In addition, as shown in fig. 9, the embodiment of the present invention further provides a preparation method for preparing the double-layer acetabular cup prosthesis according to the above embodiment, the preparation method comprising the following steps:

Step S1: the three-dimensional model of the outer cup 100 and the three-dimensional model of the inner liner cup 200 are designed according to the size of the acetabular fossa and the femoral head. Specifically, modeling software is adopted, mainly using modeling software capable of importing a three-dimensional model into a 3DP printer, designing a three-dimensional model of a double-layer acetabular cup prosthesis according to actual acetabular fossa and femoral head sizes, respectively establishing three-dimensional models of the outer cup 100 and the inner cup 200, and determining optimal matching details of the outer cup 100 and the inner cup 200.

Step S2: the three-dimensional model of the outer cup 100 and the three-dimensional model of the inner liner cup 200 are subjected to matching simulation. The three-dimensional model of the outer cup 100 and the three-dimensional model of the inner liner cup 200 are combined, matching simulation is carried out according to actual use, and whether the three-dimensional model of the outer cup 100 and the three-dimensional model of the inner liner cup 200 are suitable for the actual acetabular fossa and the femoral head or not is checked, so that an excellent connecting effect is achieved.

Step S3: the outer cup 100 is manufactured using 3D printing techniques from a three-dimensional model of the outer cup 100. After the three-dimensional model of the outer cup 100 is built, it is introduced into a 3DP printer system, and a slicing process is performed so that the 3DP printer system performs layer-by-layer printing. And the 3DP printer system screens powder and dries, and 3D printing can be performed after the printing parameters such as scanning speed, powder spreading thickness and the like are set. After the outer cup 100 is molded, the outer cup 100 is taken out from the support substrate by a wire cutting operation, and finally, the outer cup 100 is subjected to a post-treatment, such as a first chamfering treatment.

If the 3D printing technology is a laser 3D printing SLM technology, the laser power is 150W to 300W, the scanning speed is 600mm/s to 1200mm/s, the powder spreading thickness is 0.03mm to 0.06mm, and the scanning interval is 0.05mm to 0.1mm.

Specifically, in modeling, the outer contour of the femoral head prosthesis is designed to be spherical, and a porous structure layer with a thickness of 0.1 to 1mm is added on the first convex spherical surface 120 of the outer cup 100, the unit structure is set to be 0.6mm, the unit structures are uniformly distributed in the 3 directions of XYZ, and the diameter of unit cells of the porous structure layer is 0.15mm.

After three-dimensional modeling is designed and completed according to the above details, the three-dimensional models of the femoral head prosthesis and the outer cup 100 are respectively introduced into a 3DP printer system, slicing is performed, the slicing thickness is set to be 0.05 to 0.10mm, and a support substrate is added after slicing is completed.

Preparing tantalum alloy powder, sieving to obtain powder with a particle size distribution D ₅₀ of 30+ -3 μm and D ₉₀ of 45+ -5 μm, drying the sieved powder in a vacuum drying oven for 3h, and pouring into a 3D printing system for printing.

And wiping the prepared stainless steel support substrate with alcohol, then placing the stainless steel support substrate in a 3DP printer, closing a printing cabin door, and introducing nitrogen protection gas. Setting printing parameters, namely setting laser power to be 150-300W, setting the spot diameter to be 100 mu m, setting the scanning speed to be 600-1200 mm/s, setting the powder spreading thickness to be 0.03-0.06 mm and setting the scanning interval to be 0.05-0.10 mm.

After the 3D printing work is completed, the resulting outer cup 100 is cut out from the support substrate using a wire-cut method.

The outer cup 100 prepared by 3D printing is further cleaned and cleaned with a non-toxic and harmless biological cleaner.

If the 3D printing technology is an electron beam 3D printing EBM technology, the power of the electron beam is 1kW to 2kW, the scanning speed is 800mm/s to 4000mm/s, and the powder spreading thickness is 0.05 to 0.1mm.

Step S4: the liner cup 200 is manufactured using a machining process based on a three-dimensional model of the liner cup 200. Specifically, the inner liner cup is machined by means of machining, and preliminary adaptability matching inspection is performed according to the machining matching site and the outer cup 100 machined in step S3, so that machining errors are confirmed to be within a reasonable range. The machining mode comprises turning, milling, planing, grinding, polishing and the like.

After the liner cup 200 is machined according to the three-dimensional model of the liner cup 200, the lower end of the liner cup 200 has a second concave spherical surface 240 with a downward opening. The wear resistant coating is then prepared on the second concave spherical surface 240 of the liner cup 200 using a PVD coating process. Then, the liner cup 200 is cleaned with a nontoxic and harmless biological cleaner, and the liner cup 200 is again checked for matching with the outer cup 100.

In the preparation method, the outer cup 100 is prepared by adopting a 3D printing technology, the inner liner cup 200 is prepared by adopting a machining technology, and a porous structure layer is conveniently prepared on the outer cup 100 by compounding the 3D printing technology and the machining mode, and meanwhile, the excellent matching degree between the outer cup 100 and the inner liner 200 can be ensured.

It will be appreciated that since the second male and female spherical surfaces 230, 240 of the liner cup 200 require a high finish to reduce the coefficient of friction between the liner cup 200 and the outer cup 100 and between the liner cup 200 and the liner prosthesis, the second male and female spherical surfaces 230, 240 are directly machined to achieve a suitable finish, reduce roughness, reduce wear, and extend service life.

If the 3D printing method is adopted, further post-treatment is required to be performed on the liner cup 200 in the following process, so that the processing efficiency of the liner cup 200 is affected. Therefore, the lining cup 200 is directly machined to obtain proper smoothness, reduce roughness, reduce abrasion and prolong service life; moreover, when the liner cup 200 is machined, corresponding adaptation processing can be performed according to the manufacturing precision of the outer cup 100 after 3D printing, so that higher matching precision is obtained, and the problem that the use effect of the double-layer acetabular cup prosthesis is reduced due to poor matching precision of the outer cup 100 and the liner cup 200 is avoided.

While the preferred embodiment of the present application has been described in detail, the application is not limited to the embodiments, and various equivalent modifications and substitutions can be made by those skilled in the art without departing from the spirit of the application, and these modifications and substitutions are intended to be included in the scope of the present application as defined in the appended claims.

Claims

1. A dual layer acetabular cup prosthesis comprising:

The outer cup (100) is provided with a first convex spherical surface (120) for being connected with an acetabular fossa at the upper end, a first concave spherical surface (130) and a limiting groove (140) with openings facing downwards are arranged on the lower end surface of the outer cup (100), the first concave spherical surface (130) is provided with an annular groove (150), the annular groove (150) is formed by rotating an upper and lower extending central axis of the first concave spherical surface (130) as a rotation axis, the cross section of the annular groove (150) is arc-shaped, and the limiting groove (140) penetrates through the first concave spherical surface (130);

The inner lining cup (200) is provided with a second concave spherical surface (240) used for being connected with an inner lining prosthesis on the lower end surface, the upper end of the inner lining cup (200) is provided with a second outer convex spherical surface (230), the second outer convex spherical surface (230) is connected with the first concave spherical surface (130) in an adapting way, the second outer convex spherical surface (230) is provided with an annular convex part (210) and a limiting part (220), the annular convex part (210) is formed by rotating by taking a central axis extending up and down of the second outer convex spherical surface (230) as a rotation axis, the cross section of the annular convex part (210) is in a circular arc shape, the annular convex part (210) is connected with the annular groove (150) in an adapting way, the surfaces of the annular convex part (210) and the annular groove (150) are smooth, and the limiting part (220) is connected with the limiting groove (140) in an adapting way;

The lower end face of the outer cup (100) is provided with a first chamfer, the first chamfer is formed by rotating the central axis extending up and down of the first concave spherical surface (130) as a rotation axis, the first chamfer is formed by tilting the inner side of the first concave spherical surface (130) upwards outwards, the lower end face of the inner liner cup (200) is provided with a second chamfer, the second chamfer is formed by rotating the central axis extending up and down of the second convex spherical surface (230) as a rotation axis, the second chamfer is formed by tilting the inner side of the second convex spherical surface (230) upwards outwards, and the tilt angles of the second chamfer and the first chamfer are consistent;

The central angle of first indent sphere (130) is less than 180, the central angle of second outer protruding sphere (230) is less than 180, the lower terminal surface of inside lining cup (200) with the lower terminal surface of outer cup (100) is the incline plane, and looks parallel and level, spacing portion (220) with there is certain clearance in the radial of outer cup (100) between spacing groove (140), spacing groove (140) with spacing portion (220) are by interior to outside slope upward, the thickness of outer cup (100) is middle thick, both sides are thin.

2. The double-layer acetabular cup prosthesis according to claim 1, wherein the limiting groove (140) is provided with a plurality of limiting grooves and circumferentially arranged around a central axis extending up and down of the first concave spherical surface (130), the limiting portion (220) is provided with a plurality of limiting portions, and the plurality of limiting portions (220) are correspondingly arranged with the plurality of limiting grooves (140).

3. The dual layer acetabular cup prosthesis of claim 1, further comprising a set screw (300); the outer cup (100) is provided with a countersunk hole (110), the countersunk hole (110) respectively penetrates through the first concave spherical surface (130) and the first convex spherical surface (120), the fixing screw (300) is matched with the countersunk hole (110), and a thread section (310) of the fixing screw (300) is located outside the first concave spherical surface (130).

4. The double-layer acetabular cup prosthesis of claim 1, wherein the first convex spherical surface (120) is provided with a porous structural layer.

5. The double-layer acetabular cup prosthesis of claim 1, wherein the second concave spherical surface (240) is downwardly disposed with an opening, the second concave spherical surface (240) being provided with a wear-resistant coating.

6. The dual layer acetabular cup prosthesis of claim 1 wherein the outer cup (100) and inner liner cup (200) are made of one of tantalum or tantalum alloy, cobalt chromium molybdenum alloy, titanium or titanium alloy.

7. A method for preparing a double-layered acetabular cup prosthesis according to any of claims 1 to 6, comprising the steps of:

Designing a three-dimensional model of the outer cup (100) and a three-dimensional model of the inner liner cup (200) according to the sizes of the acetabular fossa and the femoral head;

Matching simulation is carried out on the three-dimensional model of the outer cup (100) and the three-dimensional model of the inner liner cup (200);

Manufacturing the outer cup (100) by adopting a 3D printing technology according to the three-dimensional model of the outer cup (100);

The liner cup (200) is manufactured using a machining process based on a three-dimensional model of the liner cup (200).

8. The method of manufacturing the liner cup (200) according to claim 7, wherein the step of manufacturing the liner cup (200) using a machining process based on the three-dimensional model of the liner cup (200) comprises the steps of:

machining the lining cup (200) according to a three-dimensional model of the lining cup (200), wherein the lower end of the lining cup (200) is provided with a second concave spherical surface (240) with a downward opening;

and preparing the wear-resistant coating on the second concave spherical surface (240) of the lining cup (200) by adopting a PVD coating process.

9. The preparation method according to claim 7, wherein the 3D printing technology is a laser 3D printing SLM technology, the laser power is 150W to 300W, the scanning speed is 600mm/s to 1200mm/s, the powder spreading thickness is 0.03mm to 0.06mm, and the scanning interval is 0.05mm to 0.1mm; or the 3D printing technology is an electron beam 3D printing EBM technology, the power of the electron beam is 1kW to 2kW, the scanning speed is 800mm/s to 4000mm/s, and the powder spreading thickness is 0.05 to 0.1mm.